"Soldier F" is to be charged over one of the most notorious cases from the Troubles: the killings of 13 unarmed Catholic demonstrators in Londonderry. There was insufficient evidence to charge a further 16 soldiers.

Following the 2010 public inquiry report which found British troops had fired first at unarmed civil-rights demonstrators in 1972, the first prosecution for murder was announced Thursday against one of the soldiers involved.

The Public Prosecution Service in the British province of Northern Ireland said it would prosecute "Soldier F" for the murders of two marchers and for a further four attempted murders but "in respect of the other 18 suspects, including 16 former soldiers and two alleged official IRA members, it has been concluded that the available evidence is insufficient to provide a reasonable prospect of conviction."

The director of public prosecutions for Northern Ireland, Stephen Herron, said he was conscious that relatives faced an "extremely difficult day," but "much of the material which was available for consideration by the inquiry is not admissible in criminal proceedings, due to strict rules of evidence that apply."

A solicitor for victims' families, Ciaran Shiels, said relatives of those who died were "disappointed that not all those responsible are to face trial."

The marchers had been protesting Britain's detention of suspected Irish nationalists in the majority Catholic area of the Bogside in Derry on what became known as Bloody Sunday, January 30, 1972.

Soldiers from the British army's elite Parachute Regiment opened fire on the marchers and killed 13 people and wounded 14 others, one of whom died later.

An initial official government probe conducted within weeks of the shootings concluded that the soldiers were blameless. Lord Widgery's 1972 inquiry stated the soldiers only fired after being fired upon.

It was only in 2010, after a 12-year inquiry that High Court Judge Lord Saville, reversed the findings of Lord Widgery's 1972 inquiry. The Saville Report said the paratroopers opened fire without warning and that none of the casualties has posed a threat.